| 摘要 |
PROBLEM TO BE SOLVED: To detect defects in a pattern with high sensitivity by constituting the device in such a manner that one light source is used, a transmission optical system and a reflection optical system can be switched, transmitted light and reflected light can be emitted at one time, and these light beams can be accepted by one sensor. SOLUTION: In this device, one light source is used and a transmission optical system 50 and a reflection optical system 60 can be switched. Transmitted light and reflected light can be emitted at one time and these light beams can be accepted in one imaging sensor 90. In this device, shutter functions 52, 62 to cut the transmitted light beam 51 and reflected light beam 61 can independently cut the respective beams 51, 61. By operating the shutter functions 52, 62, simultaneous irradiation of transmitted light and reflected light is possible. Therefore, the mask image can be observed by one imaging sensor 90 with the transmitted light, reflected light or both of transmitted/reflected light at one time. |
